Hydrodynamic and Foundation Interaction Effects in Earthquake Response of a Concrete Gravity Dam

The displacement and stress responses are presented for Pine Flat Dam to the S69E component of the Taft ground motion only, and to the S69E and vertical components acting simultaneously. For each of these excitations, the response of the dam is analyzed four times corresponding to the following four sets of assumptions: (1) Rigid foundation, hydrodynamic effects excluded; (2) rigid foundation, hydrodynamic effects included; (3) flexible foundation, hydrodynamic effects excluded; and (4) flexible foundation, hydrodynamic effects included. Based on these results, the separate effects of dam-water interaction and dam-foundation rock interaction, and the combined effects of the two sources of interaction, on earthquake response of dams are investigated.